The present invention relates to an improved method of disease therapy with cytotoxic agents, including anticancer, antimicrobial, anti-autoimmune disease and anti-organ-rejection therapy, wherein cytokines are used to prevent, mediate or reverse radiation-induced or drug-induced or antibody-induced toxicity, especially to hematopoietic cells.
Most forms of nonsurgical cancer therapy, such as external irradiation and chemotherapy, are limited in their efficacy because of toxic side effects to normal tissues and cells, because of the limited specificity of these treatment modalities for cancer cells. This limitation is also of importance when anti-cancer antibodies are used for targeting toxic agents, such as isotopes, drugs, and toxins, to cancer sites, because, as systemic agents, they also circulate to sensitive cellular compartments such as the bone marrow. In acute radiation injury, there is destruction of lymphoid and hematopoietic compartments as a major factor in the development of septicemia and subsequent death.
In the field of organ transplantation, the recipient's cellular immune response to the foreign graft is depressed with cytotoxic agents which affect the lymphoid and other parts of the hematopoietic system. Graft acceptance is limited by the tolerance of the recipient to these cytotoxic chemicals, many of which are similar to the anticancer (antiproliferative) agents. Likewise, when using cytotoxic antimicrobial agents, particularly antiviral drugs, or when using cytotoxic drugs for autoimmune disease therapy, e.g., in treatment of systemic lupus erythematosis, a serious limitation is the toxic effects to the bone marrow and the hematopoietic cells of the body.
Many different approaches have been undertaken to protect an organism from the side effects of radiation or toxic chemicals. One approach is to replace bone marrow cells after toxicity has developed. Another is to inject a chemical blocker which competes for the site of action of the toxic drug. Still another method is to give agents which affect DNA repair mechanisms such as the chemical radioprotection afforded by thiol compounds.
Neta et al. (J. Immunol. 136:2483-2485, 1986) showed that pre-treatment with recombinant interleukin-1 (IL-1) protects mice in a dose-dependent manner from the lethal effects of external beam irradiation, when the IL-1 was given 20 hr before irradiation. Administering IL-1 4 hr before irradiation significantly reduced the radioprotective effects of IL-1. However, IL-1 cannot be administered too long before irradiation, because these authors also found that at 45 hr before irradiation, a drastic reduction in survival, as compared to the mice given IL-1 at 20 hr before irradiation, was achieved. Thus, this study indicated that IL-1 should be given at a critical period before lethal irradiation.
This was the first evidence that a cytokine, which acts as a differentiation-inducing and maturation-inducing agent for a variety of cells, can initiate radioprotective events in vivo when given prior to external beam irradiation. However, other kinds of immunomodulators have been reported to confer radioprotection. Numerous impure microbial components, such as lipopolysaccharide, which are now recognized to enhance hematopoietic and immune functions, were shown to have radioprotective activity more than thirty years ago (Smith et al., Am J. Physiol. 109:124-130, 1957; Mefford et al., Proc. Soc. Exp. Biol. Med. 83:54-63, 1953; Ainsworth and Chase, Proc. Soc. Exp. Biol. Med. 102:483-489, 1959).
The effects of IL-1 are mediated through the induction of colony stimulating factor (CSF) (Vogel et al., J. Immunol. 138:2143-2148, 1987), one of many hematopoietic growth factors induced by IL-1 stimulation of endothelial cells (Broudy et al., J. Immunol. 139:464-468, 1987; Lee et al., Exp. Hematol. 15:983-988, 1987; Takacs et al., J. Immunol. 138:2124-2131, 1985). However, it was shown by Neta et al. (Lymphokine Res. 5:s105, 1986; J. Immunol. 140:108-111, 1988) that human recombinant granulocyte CSF (rG-CSF) or granulocyte-macrophage CSF (GM-CSF) alone do not confer radioprotection, but do work synergistically with IL-1 to prevent radiation death in mice. Interestingly, this study also showed that mouse strains react differently to radiation and the radioprotection of IL-1, thus making extrapolation of such effects to other species, especially humans, difficult. This lack of radiation protection by the CSF's alone is in contrast to their being able to induce a recovery of neutropenia in mice treated with the anticancer drug, 5-fluorouracil (5-FU) (Moore and Warren, Proc. Natl. Acad. SCi. U.S.A. 84:7134-7138, 1987). Likewise, these authors reported that the neutropenic effects of 5-FU could be reduced by treating the mice with the cytokine 4 hr after giving the 5-FU, and that there was a synergy of IL-1 and G-CSF in acceleration of neutrophil regeneration. These studies indicate, when compared to the work of Neta et al. (cited above) for radiation protection, that different time schedules are needed for IL-1 application in drug-induced or external beam irradiation-induced myelosuppression, and that the cytokines can act differently in their ability to prevent radiation- or chemotherapy-induced myelosuppression.
Although it has been shown that an important function of IL-1 is as an immune stimulator, a plethora of other properties have been ascribed to this substance, as contained in the reviews of Dinarello (Rev. Infectious Dis. 6:51-95, 1984; Oppenheim et al., Immunology Today 7:45-56, 1986; Lomedico et al., Cold Spring Harbor Symp. Quantit. Biol. 51:631-639, 1986):
1. Stimulation of mouse thymocyte activation (Lomedico et al., Nature 312:458, 1984); PA1 2. stimulation of human dermal fibroblast proliferation (Dukovich et al., Clin. Immunol. Immunopathol. 38:381, 1986; Gubler et al., J. Immunol., 136:2492, 1986); PA1 3. stimulation of IL-2 production (Kilian et al., J. Immunol. 136:4509, 1986); PA1 4. stimulation of PGE.sub.2 and collagenase production by human rheumatoid synovial cells and dermal fibroblasts (Dukovich et al., Clin. Immunol. Immunopathol. 38:381, 1986; Gubler et al., J. Immunol. 136:2492, 1986); PA1 5. stimulation of arachidonic acid metabolism in liver and smooth muscle cells (Levine and Xiao, J. Immunol. 135:3430, 1985); PA1 6. stimulation of metallothionein gene expression in human hepatoma cells (Karin et al., Mol. Cell. Biol. 5:2866, 1985); PA1 7. stimulation of synthesis of certain hepatic acute-phase proteins (Bauer et al., FEBS Lett. 190:271, 1985; Ramadori et al., J. Exp. Med. 162:930, 1985; Perlmutter et al., Science 232:850, 1986; Hall et al., Lymphokine Res. 5:87, 1986); PA1 8. stimulation of bone resorption in vitro (Gowen and Mundy, J. Immunol. 136:2478, 1986); PA1 9. stimulation of ACTH production in a pituitary tumor cell line (Woloski et al., Science 230:1035, 1985); PA1 10. cachectin-like activity (tumor necrosis factor) to suppress lipoprotein lipase activity in adipocytes (Beutler et al., J. Exp. Med. 161:984, 1985); PA1 11. activity as B-cell growth and differentiation factor (Pike and Nossal, Proc. Natl. Acad. Sci. USA 82:8153, 1985); PA1 12. stimulation of platelet-activating factor production in cultured endothelial cells (Bussolino et al., J. Clin INvest. 77:2027, 1986); and PA1 13. stimulation of monocyte- or T-cell-mediated tumor cell cytotoxicity (Lovett et al, J. Immunol. 136:340-347, 1986; Onozaki et al., J. Immunol. 135:314-320, 1985; Farrar et al., J. Immunol. 123:1371-1377, 1980).
Whereas the above listing refers to in vitro effects of IL-1, IL-1 in vivo has been shown in rodents to (1) be pyrogenic (McCarthy et al., Am. J. Clin. Nutr. 42:1179, 1985; Tocco-Bradley et al., Proc. Soc. Exp. Biol. Med. 182:263, 1986), (2) promote leukocytosis and hypozincemia (Tocco-Bradley et al., Proc. Soc. Exp. Biol. Med. 182:263, 1986), and hypoferremia (Westmacott et al., Lymphokine Res. 5:87, 1986), (3) induce a transient suppression of food intake (McCarthy et al., Am. J. Clin. Nutr. 42:1179, 1985), (4) stimulate accumulation of procoagulant activity in endothelial cells (Nawroth et al. Proc. Natl. Acad. Sci. USA 83:3460, 1986), (5) induce a local inflammatory response in the skin (Granstein et al., J. Clin. Invest. 77:1020, 1986), and (6) inhibit the growth of murine syngeneic tumors (Nakamura et al., Gann 77:1734-1739, 1986). Therefore, the demonstration that mice can be protected from lethal doses of external beam irradiation by prior administration of IL-1 (Neta et al., J. Immunol. 136:2483, 1986), alongside all these other actions, does not predict that it will be useful in humans when given during and/or after external beam irradiation, internally administered irradiation, or systemic cytotoxic chemotherapy.
Cancer therapy using anticancer cytotoxic radioisotopes and drugs is well known. It is also well known that radioisotopes, drugs, and toxins can be conjugated to antibodies or antibody fragments which specifically bind to markers which are produced by or associated with cancer cells, and that such antibody conjugates can be used to target the radioisotopes, drugs or toxins to tumor sites to enhance their therapeutic efficacy and minimize side effects. Examples of these agents and methods are reviewed in Wawrzynczak and Thorpe (in Introduction to the Cellular and Molecular Biology of Cancer, L. M. Franks and N. M. Teich, eds, Chapter 18, pp. 378-410, Oxford University Press, Oxford, 1986), in Immunoconjugates. Antibody Conjugates in Radioimaging and Therapy of Cancer (C.-W. Vogel, ed., 3-300, Oxford University Press, New York, 1987), in Dillman, R.O. (CRC Critical Reviews in Oncology/Hematology 1:357, CRC Press, Inc., 1984), in Pastan et al.(Cell 47:641, 1986), in Vitetta et al. (Science 238:1098-1104, 1987) and in Brady et al. (Int. J. Rad. Oncol. Biol. Phys. 13:1535-1544, 1987). Other examples of the use of immunoconjugates for cancer and other forms of therapy have been disclosed, inter alia, in Goldenberg, U.S. Pat. Nos. 4,331,647, 4,348,376, 4,361,544, 4,468,457, 4,444,744, 4,460,459, 4,460,561 and 4,624,846 and in related pending application U.S. Ser. No. 005,355 (hereinafter, the "Goldenberg patents"), and in Rowland, U.S. Pat. No. 4,046,722, Rodwell et al., U.S. Pat. No. 4,671,958, and Shih et al., U.S. Pat. No. 4,699,784, the disclosures of all of which are incorporated herein in their entireties by reference.
Use of cytotoxic agents, including immunoconjugates for anti-microbial, particularly antiviral, therapy, for autoimmune disease therapy, as well as for the therapy of the recipient host's rejection of foreign organ transplants, are likewise burdened by the hematopoietic side effects of these agents, thus limiting their therapeutic efficacy.
Antibodies themselves can be used as cytotoxic agents, either by virtue of their direct, e.g., complement mediated, action upon, e.g., invading microorganisms or proliferating tumor cells, or by an indirect mode, e.g., through mobilization of T-cells (e.g., killer cells), an action known as antibody-directed cellular cytotoxicity (ADCC). Such antibody cytotoxicity, denoted herein as unconjugated cytotoxic antibody therapy, can also result in compromise of elements of the hematopoietic system, and such adverse side effects can be prevented, mitigated and/or reversed with adjunctive cytokine therapy.
A need therefore continues to exist for methods of preventing, mitigating or reversing toxicity to myeloid and hematopoietic cells, which is a limiting side effect of treatment of various diseases in humans with cytotoxic agents.